Fuser members overcoated with fluorocarbon elastomer containing tin oxide

Abstract

A fuser member useful for heat-fixing an electrographic toner to a substrate. The fuser member has a core and a layer overlying the core. That layer includes a cured fluorocarbon random copolymer having subunits with the general structures: -(CH2CF2)x-, -(CF2CF2)z-, and <IMAGE> where x is from 30 to 90 mole percent, y is from 10 to 70 mole percent, and z is from 0 to 34 mole percent. The layer incorporates particulate filler. The filler includes tin oxide and a material selected from the group consisting of alkali metal oxides, alkali metal hydroxides, and combinations thereof. The filler has a total concentration in the layer of from about 25 to 50 percent of the total volume of the layer. The tin oxide has a concentration of from 20 to 40 percent of the total volume of the layer.

What is claimed is: 
     
       1. A fuser member comprising: a core and a layer overlying said core, said layer comprising a cured fluorocarbon random copolymer comprising subunits having the general structures:   --(CH.sub.2 CF.sub.2).sub.x --, --(CF.sub.2 CF.sub.2).sub.z --,     and ##STR6## wherein x is from 30 to 90 mole percent,   y is from 10 to 70 mole percent, and   z is from 0 to 34 mole percent; said layer further comprising particulate filler, said particulate filler including tin oxide and a material selected from the group consisting of alkali metal oxides, alkali metal hydroxides, and combinations thereof; said particulate filler having a total concentration in said layer of from about 25 to 50 percent of the total volume of said layer, said tin oxide having a concentration of from 20 to 40 percent of the total volume of said layer.     
     
     
       2. The fuser member of claim 1 wherein said alkali metal hydroxide comprises calcium hydroxide and said alkali metal oxide comprises magnesium oxide. 
     
     
       3. The fuser member of claim 1 wherein said polymer is nucleophilic addition cured. 
     
     
       4. The fuser member of claim 1 wherein said polymer is crosslinked by biphenolic residues. 
     
     
       5. The fuser member of claim 1 wherein x is from 40 to 80 mole percent, y is from 10 to 60 mole percent, and z is from 0 to 34 mole percent. 
     
     
       6. The fuser member of claim 1 wherein x is from 42 to 75 mole percent, y is from 14 to 58 mole percent, and z is 0. 
     
     
       7. The fuser member of claim 1 wherein z is 0. 
     
     
       8. The fuser member of claim 1 wherein x is greater than 40 mole percent. 
     
     
       9. A fuser member useful for heat-fixing an electrographic toner to a substrate, said fuser member comprising: a core, a base cushion superimposed on said core and an outer layer superimposed on said base cushion, said outer layer comprising a bisphenol cured fluorocarbon random copolymer comprising subunits having the general structures:   --(CH.sub.2 CF.sub.2).sub.x --, --(CF.sub.2 CF.sub.2).sub.z --,     and ##STR7## wherein x, y, and z are selected such that fluorine atoms represent at least 70 percent of the total formula weight of said subunits;   said outer layer having filler particles dispersed therein, said filler particles further comprising:   particles selected from the group consisting of alkali metal oxides and alkali metal hydroxides in a concentration of from about 5 to 20 percent of the total volume of said outer layer; and   tin oxide particles in a concentration of from 20 to 40 percent of the total volume of said outer layer.   
     
     
       10. The fuser member of claim 9, wherein the concentration of tin oxide particles is from 30 to 40 percent of the total volume of said outer layer. 
     
     
       11. A fuser member useful for heat-fixing an electrographic toner to a substrate, wherein said fuser member comprises a core, a base cushion layer overlying said core, and an outer layer superimposed on said base cushion, said outer layer comprising a cured fluorocarbon random copolymer comprising subunits having the general structures:   --(CH.sub.2 CF.sub.2).sub.x --, --(CF.sub.2 CF.sub.2).sub.z --,     and ##STR8## wherein x is from 10 to 90 mole percent,   y is from 10 to 70 mole percent, and   z is from 0 to 34 mole percent; said outer layer further comprising particulate filler, said particulate filler including tin oxide and a material selected from the group consisting of alkali metal oxides, alkali metal hydroxides, and combinations thereof; said particulate filler having a total concentration in said outer layer of from about 25 to 50 percent of the total volume of said outer layer, said tin oxide having a concentration of from 20 to 40 percent of the total volume of said outer layer.